Rocket-engine and reaction-motor missile



July 27, 1954 K. M. NoRDFoRs ROCKET-ENGINE; AND REACTION-MOTOR MISSILEFiled lJune 7, 195o Zmventor KURT MARTI/V NORD ORS Gttorneg PatentedJuly 27, 1954 ROCKET-ENGINE AND REACTION-MOTOR MISSILE Kurt MartinNordfors, Karlskoga, Sweden, as-

signor to Aktiebolaget Bofors, Bofors, Sweden, a joint-stock company ofSweden Application June 7, 1950, Serial No. 166,594 Claims priority,application Sweden July 7, 1949 4 Claims.

matically operative to impel the missile forward in its flight afterthere has been imparted to it by a gun or other appropriate launchingmeans an initial velocity adequate to permit effective operation of thesaid engine. But such missiles require an initial velocity ofconsiderable magnitude to make the engine work satisfactorily and theseare bulky and expensive because-of the service required of them.

The present invention relates to an improvement in missiles of thisclass that in combination with a generally similar engine there isembodied auxiliary propulsion means of so-ca'lled rocket characteristicswhereby the missile may be launched from a gun or the like at lowerinitial or muzzle velocity and then attain the velocity requisite foroperation of the rain jet engine under the impulse of a rocket charge`carried inside the missile; after the exhaustion of such charge the ramjet is automatically brought into pla-y to further propel the missile atthe velocity then attained or a higher one until exhaustion of the ramjet-fuel or arrival at a target, whichever rst occurs.

It is therefore a principal object of the invention to provide in aprojectile or other missile having reaction propulsion means, auxiliaryrocket type propulsion means in which rocket fuel is initially consumedin a combustion chamber and the exhaust gases discharged throughail-exhaust nozzle and after combustion of said fuel is automaticallyfurther propelled by a ram jet using the same combustion chamber andexhaust nozzle to afford greatly increased range while the necessity ofinitially discharging it at very high velocity is obviated.

Another object is to provide a projectile or missile of the characteraforesaid wherein the pressures generated by the combustion of therocket fuel automatically maintain theram jet engine air intake portclosed during flight until exhaustion of the rocket fuel and then allowthe said port to open for intake'of air to support combustion of the ramjet fuel and thereby supply .further impulse to the travel of themissile.

YOther objects, .purposes andadvantages of the invention willhereinafter more fully appear or will be understood from the followingdescription of a preferred embodiment of it diagraminaticallyillustrated in the accompanying drawing, in which Fig. l is an axialsection partly in elevation of a missile embodying the invention as itappears prior to its discharge from a gun or the like; and

Fig. 2 is a corresponding View showing the missile as it appears inflight after exhaustion of the rocket fuel and upon initiation of theoperation of its contained ram jet engine.

Referring now more particularly to the drawing the missile illustratedtherein comprises an outer casing or shell i of generally cylindricalform within which is coaxially disposed an inner body 2 which may carrya bursting charge or the like. The leading end of the outer casing iscurved inwardly and :feathered as at 3 for snug engagement with thesubstantially conoidal nose fl of the inner body 2 and adapted to formtherewith an annular port 5 when the casing l and body 2 are movedaxially relatively to each other from the relative positions shown inFig. l to those shown in Fig. 2. Within the outer casing rearwardly ofthe port 5 the inner surface of the outer casing and the outer surfaceof the inner body are substantially cylindrical and form between them acombustion chamber 6 the walls of which initially are dened by a layer'l of rocket fuel overlying a subjacent layer 8 of ram jet fuel whichmay be applied in any suitable manner to the opposed walls of the casingand body. At their rear ends these parts are formed to provide anexhaust nozzle 9 the conformation of which is appropriately designed toproduce a reaction impelling the missile forward as combustion productsare discharged through it at high velocity.

The outer casing at a suitable position is desirably provided with anannular sealing or packing ring I I] adapted for cooperation with thebore of a gun barrel or other suitable launching mechanism to preventescape through said bore around the missile of the gases emanating fromthe initial propulsive charge while it is in the bore, the ring alsoserving to impart axial rotation to the missile in the ordinary mannerif the bore is riiled.

The missile is initially charged into the gun or other launchingapparatus in the condition shown in Fig. l, that is, with port 5 closedby tight engagement of nose ll of the inner body with feathered edge 3of the outer casing, and this gas seal combined with the seal betweenthe missile as a whole and the gun barrel aiforded by packing ring l0enables the full propulsive `effect of the launching charge to reactagainst muzzle of the firing mechanism a discharge of combustionproducts through port 9 resulting from combustion of rocket fuel limparts additional impetus to the missile and further accelerates itsflight, resultant pressure in the combustion chamber retaining aneffective seal between the leading feathered edge 3 0f the outer casingand nose d of the body until exhaustion of the rocket fuel.` Thereafter,upon decline of this pressure the atmospheric air pressure on nose lltends to retard the inner body and permit the outer casing to moveforwardly relatively thereto, admitting air under pressure to combustionchamber 6 through the now open port 5. The ram jet fuel 8 is thereuponignited and products of its combustion are discharged at high velocitythrough exhaust nozzle i3 which is so designed as to afford a largeropening during the ram jet operation than during combustion of therocket fuel as a result of the above described relative axial movementof the parts. The missile is therefore further propelled by the actionof the ram jet to greatly increase its range and velocity as comparedwith comparable missiles depending for their range entirely upon thepropulsive force imparted by the initial charge of the gun or otherlaunching device.

The missile described herein is of course adapted to be operated withthe aid of liquid or gaseous as well as solid fuel or any desiredcombination of fuels in these several phases and since the rocket fuelrequires no air to support its combustion it is obvious the entire spacebetween the outer casing and inner wall may entirely be filled with thisand other fuel, consumption of the rocket fuel during the initial stageof flight evacuating space for the passage of air through the interiorof the outer casing during subsequent ram jet operation.

Of course it is obvious that means may be provided for holding the frontand rear portions of the inner body in coaxial relation with the outershell while permitting their relative axial movement, for example, aplurality of radial stays fixed to the inner body, slidably engaging theinner wall of the outer shell and where the rear stays are preferablyarranged to engage the constricted rear portion of said wall adjacentthe exhaust nozzle or some other suitable abutment at maximum operativeopen position of i it will be understood I do not desire or intend .i

thereby to be limited or confined in any way as changes andmodifications in the form, construction and relationship of the severalparts and instrumentalities employed other than as herein suggested willreadily occur to those skilled in the art and may be made if desiredwithout departing from the spirit and scope of the invention as definedin the appended claims.

Having thus described my invention, I claim and desire to protect byLetters Patent of the United States z 1. A missile comprising coaxialrelatively movable parts including a substantially cylindrical hollowouter casing having a constriction at its forward end and asubstantially cylindrical inner body having a conoidal nose of greatermaximum diameter than the minimum diameter of said constrictioncooperative with said constriction to provide an annular port adapted tobe closed by relative axial movement of the parts,

the rear ends of said parts forming a reactive discharge nozzle, ram jetengine fuel disposed interiorly of the casing, and rocket-engine fueladjacent thereto, the reaction of combustion of said rocket-engine fuelmaintaining said parts in relative positions closing said annular portand the resistance of the atmosphere in flight inducing relativemovement of the parts to open said port on exceeding said reaction.

2. A missile as defined in claim 1 in which said ram jet engine fuelcomprises a layer of combustible material proximate the inner wall ofthc casing between said port and said nozzle and said rocket-engine fuelcomprises material adapted for selfsust'aining combustion proximate theinner surface of said rst material whereby in flight of the missileinternal pressure generated by combustion of said last mentionedmaterial reacts against said parts to maintain said port closed and ondecrease in said pressure reaction of atmospheric pressure against saidconoidal nose effects relative movement of said parts to open said portfor passage of atmospheric air under pressure therethrough to supportcombustion of the first mentioned material.

3. A missile as defined in claim 1 in which said ram jet engine fuelcomprises a combustible material forming layers adherent respectively tothe opposed surfaces of said parts within the missile and saidrocket-engine fuel comprises materiai adapted for self-sustainingcombustion interposed between opposed surfaces of said layers whereby iniiight of the missile internal pressure generated by combustion of saidlast mentioned material reacts against said parts to maintain said portclosed and on decrease in said pressure reaction of atmospheric pressureagainst said conoidal nose effects relative movement of said parts toopen said port for passage of atmospheric air under pressuretherethrough to support combustion of the first mentioned material.

4. A missile comprising coaxial relatively movable parts including asubstantially cylindrical hollow outer casing having a constriction atits forward end and a substantially cylindrical inner body having aconoidal nose normally engaged therewith adjacent its zone of maximumdiameter, said maximum diameter being greater than the minimum diameterof said constriction, the rear ends of said parts defining between thema discharge nozzle, ram jet fuel disposed in the casing intermediatesaid nose and said nozzlek and rocket-engine fuel likewise in the casingproximate the ram jet fuel whereby following discharge of the missileand subsequent combustion of the rocket-engine fuel the parts remain innormal position but thereafter move axially relative to each other tosimultaneously open a passage for air between the nose of the body andthe forward end of the casing and enlarge the effective area of thedischarge nozzle preparatory to combustion of the ram jet fuel.

References Cited in the file of this patent (3rd addition to NO.779,655)

